WASHINGTON — The tea party movement roars into the Republican presidential spotlight Monday night, as grassroots conservative-coalition members are scheduled to question GOP candidates at a Tampa, Fla., debate.

The two-hour debate, co-sponsored by the Tea Party Express and CNN, promises to include some topics that rarely come up in national political forums, such as the candidates’ views of the Constitution and the Federal Reserve.

The debate, which begins at 8 p.m. EDT, will be closely watched because the tea party movement, through a loose collection of grassroots groups barely two years old, helped elect scores of Republicans to Congress last year.

This year, Republican presidential candidates are aggressively courting the movement’s eager-to-work followers and trying to tap into their influential social and fundraising networks.

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Texas Gov. Rick Perry, Minnesota Rep. Michele Bachmann, the founder of the House of Representatives Tea Party Caucus and other diehard conservatives are already activists’ favorites. Former Massachusetts Gov. Mitt Romney and former Utah Gov. Jon Huntsman are not; they’re perceived as too moderate and compromising.

But in his economic blueprint, released last week, Romney lauded the movement, saying, “The rise of the tea party is a classic instance of the self-correcting forces of American democracy in action.”

He still has a fight ahead. Tea party activists are particularly adamant that the 2010 federal health care law be repealed, and the Massachusetts near-universal health care plan that Romney signed into law is considered its model.

“Romney has good ideas and can articulate them well. But he doesn’t have credibility,” said David Woodard, a Clemson University political scientist and also a Republican consultant and author of “The New Southern Politics.”

Perry, on the other hand, who overtook Romney in most national polls of Republican voters last month, is regarded warmly by tea partiers.

“He’s not a perfect candidate. Bachmann is better. But I think Perry may have a better chance of winning,” said Judson Phillips, founder of Tea Party Nation.

The Monday debate audience at the Florida State Fairgrounds is expected to consist largely of tea party activists, who will be asking questions. Also quizzing the panel will be movement loyalists from remote locations.

To help build momentum, the Tea Party Express has led a cross-country caravan of activists who have been stopping for rallies across the nation. The buses started rolling in Napa, Calif., August 27.

“We want to focus on fixing the economy and reducing the size of government,” said Sal Russo, Tea Party Express co-founder, speaking from one of the buses.

The tea party is not monolithic. The movement is “decentralized,” as Rep. Allen West, R-Fla., one of two black House Republicans elected with strong tea party support, put it. But he acknowledged that members’ views are similar, and as a result, “the tea party has had a lot of influence on the conversation.”

But activists’ approaches vary widely. Some want to see candidates get tougher. “Republicans need to be having a cage fight to see who can best eliminate all the government waste,” said Phillips. “What have we heard so far from these Republicans? Crickets.”

Others want more of an emphasis on the Constitution.

“We should ask them their constitutional reasoning for wanting to legalize illegal aliens. Where do they find that authorization?” asked Jerry DeLemus, chairman of the Granite State Patriots Liberty Political Action Committee, which includes several New Hampshire tea party groups.

“I want to know how they will stop him from going to a QE3,” said Dugan. In recent years, the Fed has purchased government bonds in an effort to stimulate the economy by lowering interest rates. The program, pursued twice, is called “quantitative easing,” or QE1 and QE2

Some conservatives think that by doing that, the Fed has strayed from its central mission. “The Fed’s first mandate is a stable currency,” said Dugan.

Russo, a Sacramento, Calif.-based political consultant, takes a somewhat more practical approach to the debate, saying all the candidates are largely saying the right things.

“They’ve all been addressing tea party issues,” he said.

Russo estimated that only about 5 percent of tea party sympathizers are “the ones who hold signs and come to rallies and make noise.” Another 30 percent, “if asked will say yes, I’m a card-carrying member, even though there’s no card,” he said.

Another big bloc is people Russo called “hesitant” to say openly they’re tea party loyalists but “they’re totally in sync with us on economic issues.”

The public reflects that view. The latest Quinnipiac University poll, taken August 16-27, found 29 percent viewed the tea party movement favorably, while 42 percent viewed it unfavorably — and 29 percent hadn’t heard enough about it. Only 12 percent considered themselves part of the movement. The poll involved 2,730 people. Margin of error was 1.9 percentage points.

Yet the tea party claimed success in 2010, particularly as activists helped defeat, or discourage from seeking re-election, seven mainstream or incumbent Republican senators. Three of the seven tea party-favored replacements lost in the general election — seats where the GOP was thought to have a decent chance with more moderate candidates.

Still, Republicans see the Monday debate as crucial to any presidential candidate’s hopes.

“The tea party is articulating something a lot of people want to hear,” Woodard said.